I’m giving some serious thought to getting myself an electric bike so that I can extend my commute all the way to work without dying of exhaustion toward the middle of the week.

My impression is that the majority of electric bikes on the market, except for the seriously expensive ones are heavy, low-end clunkers using the additional power to breathe life into an otherwise moribund frame.

My current plan is to build a lightweight single speed bike using a Resident Evil triple-butted steel frame I bought off Wiggle for $109. Most of my commute is going to be fairly flat and with the additional power the few hills should not be a problem. The advantage of being single-speed is that it significantly simplifies the bike and the build.

I haven’t decided upon the gearing but I’m thinking something like 46/17 or 48/18. I haven’t made any decisions about the electrics but currently I rather like the Golden Motor Magic Pie 3. Mainly because it is advertised as having lots of torque and it's power output can be adjusted down to 250W so I'll still be legal.

Any thoughts or comments would be appreciated.

It would not be at all strange if history came to the conclusion that the perfection of the bicycle was the greatest achievement of the nineteenth century.

Chosen for a number of reasons. Major one being the ease of changing a tire when punctured on a commute. I know removal of the wheel from the frame isn't absolutely neccessary when patching but on a commute to work easier to just rip the tube out and replace. Bit harder to do with a hub motor with torque arms fitted and the wiring etc.

Other one being the batteries are small, lightweight and capacity easily varied based on range of commute.

The whole thing can go on or off the bike in a manner of minutes if need be.Cheer,Glenn

(PS - no interest in the business other than owning one of the drives)

Thanks for the input. I hadn't thought of using a much simplier friction drive . I like simplicity plus keeping the weight down as even after being converted I want to be able to ride the bike without power assistance. However, what does concern me somewhat is what the unit would be like in the wet. Wouldn't it fill up with crud and would there be slippage between the unit and the rear bike wheel.

It would not be at all strange if history came to the conclusion that the perfection of the bicycle was the greatest achievement of the nineteenth century.

Yes - wet tires do cause problems with friction drives. There are various methods of increasing friction between the drive and the tire but these lead to greater tire wear.

The motor spins quite fast so I'm not sure how much water would actually ingress during a ride. References are made in the installation to wet conditions so...... But to be honest I'm more a fair weather commuter, cycling in peak hour traffic can be dangerous enough never mind dark wet commutes. I take the bus then

I have hub drive bikes as well and although the hub is sealed, the electronics with that one are more susceptible to water than the friction drive.

I like this idea. I know you mentioned single speed but running the assist through gears is probably the most efficient when you have limited power and battery.

John

John,

Thanks for the link – there is lots there to read. My decision for a single-speed is for reasons of simplicity plus I have only a few hills to negotiate. My decision for a front hub drive is also for reasons of simplicity but accept that running through the gears would be more efficient.

I’m planning on around 125 watts of input from me plus the motor (350 Watts) running at about half power will give me a total of around 300 watts plus a good reserve. This gives me only slightly less power than that of a first-class athlete (according to your chart). I’m hoping that this will give me a cruising speed of around 30 kph and not be too badly affected by hills and headwinds.

I’ve made no decision on which kit as yet but the Solar Bike Long Range Kit is the current favourite. My research on batteries suggests that they don’t like being fully discharged so with the 16 AmpHr battery the commute to work (where I can recharge) will only take it down to about half and then recharge again overnight at home.

It would not be at all strange if history came to the conclusion that the perfection of the bicycle was the greatest achievement of the nineteenth century.

I have Mr Tuffy tyre liners in my tyres. When you fit them, make sure you iron the ends until they are really thin (put it between several layers of baking paper so that you don't melt it onto the iron). Should reduce the risk of a puncture massively.

You could fit a schlumph ?? gearing system. That way you'll have a high and a low and still a simple build. If you're going to build it yourself, be prepared for some breakdowns. That is why you might want a low gear. Getting a "heavy" Ebike up a hill with a single speed would really suck!

Thanks for the comment Cachexian. I'm giving serious though to putting in a Sturmey-Archer S2C rear hub which would give me 2 gears. The build is progressing slowly, basically just collecting parts as the $$$ become available.

I hope to post some pictures over the next couple of weeks.

It would not be at all strange if history came to the conclusion that the perfection of the bicycle was the greatest achievement of the nineteenth century.

I've finished collecting all the various bits & pieces to build my Evil single-speed commuter. I've decided against the Sturmey-Archer 2-speed read hub. There are three reasons for this:1. I've read several poor reviews that cast doubt its longevity;2. Cost;3. Weight4. Not certain if it's even needed.

Ooops that was 4 reasons

Next weekend will, be with a little luck when it all comes together. At first I'll keep it non-electric just to get the feel of it and make certain that all is good.

Pics soon

It would not be at all strange if history came to the conclusion that the perfection of the bicycle was the greatest achievement of the nineteenth century.

Still got some work to do on it. The cable ties holding the brake cable on the top-tube need to be replaced with proper clamps, the brakes have to be replaced with some with a longer reach and a bottle cage installed. So far I've only ridden it up and down the drive as the brakes are working on the tyres however it feel light, fast and comfortable.

The handlebars came from Pushies Galore and cost $5 and the saddle bag cost $2 from the same source. The tyres are Michelin Lithion 2s and were around $20 from Wiggle, the frame was $109 also from Wiggle. The rims are 36H Campy strada that I had hanging up in the garage. The pedals will need to be replaced with something better, but that can wait. The other bits and pieces are from various LBSs or eBay or had lying around.

It would not be at all strange if history came to the conclusion that the perfection of the bicycle was the greatest achievement of the nineteenth century.

It’s been a long drawn out process but the SS is complete so now it’s time to turn my attention to buying the conversion kit. I’ve pretty much decided upon a 350 watt front wheel hub with a battery of at least 16 amp-hrs.

I’ve been asking the odd question of Matt at Solar Bike who has been really helpful. Currently Solar Bike is the front runner but any suggestions as to other possible suppliers would be appreciated. Also any good or bad experiences would be good to know about.

It would not be at all strange if history came to the conclusion that the perfection of the bicycle was the greatest achievement of the nineteenth century.

My electric bike project is drawing to an end. Although I’ve still got a couple of minor matters to attend to, I thought I’d post a few comments here. I ended up buying an Ezi-go 250W front hub motor and an Amazing Energy Limited 36V 10Ah LiFePO4 battery.

My original gearing of 46/18 seems a little too low as I am tiring not because of the effort but because of the high cadence. The plan now is to use the motor to get up to speed and then to mainly rely upon peddling for cruising. I’m going to change to 46/17 and see if that’s an improvement or not.

Based upon 3 trips of 15 kms each I’m using between 7.8 and 4.5 watt-hrs/km. The higher figure was when hammering into a strong wind at 30 kph without any regard to usage. The lower figure was when just cruising along in the mid-20s on a calm morning. The average electricity cost is working out at around 16 cents per 100 km.

The original plan was to extend my commute to 35 kms each way but this hasn’t happened as yet due to a combination of laziness combined with major tyre problems. This has meant that I’m staying with the shorter distance until I’m confident that all is well. Over the longer distance I still should have plenty left in the battery as my calculations suggest that the depth of discharge will be at worst 70%.

It would not be at all strange if history came to the conclusion that the perfection of the bicycle was the greatest achievement of the nineteenth century.

I completed my first commute to Wooloowin Station on Friday (71 kms return) without any issues. On the outward journey there was a modest tailwind and with a light throttle I averaged around 25 kph. I used 109.5 watt-hrs giving me a depth of discharge of 30% and a usage of 3.1 watt-hrs per km.

On the return journey there was a headwind of over 40 kph so I used the motor for almost the entire journey. Despite the unfavourable conditions I was able to maintain a speed of around 20 kph. I have no idea how discharged the battery was but certainly more than on the outward journey.

Over the weekend I swapped the original 18 tooth rear cog for a 17 tooth cog.

This morning in calm conditions again with a light throttle and almost constant peddling I maintained a speed of around 26 kph and used a mere 47.7 watt-hrs for a 15 km journey so my usage was 3.1 watt-hrs per km. The higher gear ratio seems to be an improvement as I can ride with a lower cadence.

The electricity cost is working out at around 15 cents per 100 kms.

Only time will tell but currently I’m thinking that the project has produced what I was intending.

It would not be at all strange if history came to the conclusion that the perfection of the bicycle was the greatest achievement of the nineteenth century.

For tyre puncture prevention I can STRONGLY recommend Mr Tuffy's tube liners. I have Schwalbe Stelvios (which have some puncture prot built in). I had about a puncture a week until I installed them and not a single one in 2 years since.

I took the advice I read somewhere on a forum and ironed the ends between baking paper to prevent the ends rubbing the tube.

I've done a couple of hundred kms on it now with no punctures. So all is now good on that front. Mr Tuffy Tyre Liners

I've still got a couple of set-up issues to resolve. The main one being that I'm getting numb hands. I suspect that the reason is because I'm putting less pressure on the pedals there is more weight being carried by my hands. I've added another spacer to the headset which seems to have helped. The next step will be to try it with the saddle moved forward. If all else fails a shorter stem might help.

It would not be at all strange if history came to the conclusion that the perfection of the bicycle was the greatest achievement of the nineteenth century.

Would you believe that one mechanic at a LBS advised me not to install them because they cause punctures? He said they rub the tube and eventually wear it out. Well I don't know if it's because of the ironing thing that I did to feather out the ends or just dumb luck but I haven't had that problem.

I've now done several thousand kilometers with the electric assist so perhaps this is a good time to review the project.

When I was trialing the bike as an unassisted single speed I found that a gear ratio of 46/18 to be a good compromise. With the electric assist I didn't need the lower gearing for climbing and acceleration so I changed the freewheel to 17 and finally to 16 teeth. Currently 46/16 allows me to contribute to the bike's total power without an insane cadance. I'll continue to trial the 16 freewheel for another week or so, there remains a possibility that I'll be changing the chain ring for a 48 tooth.

I purchased the conversion kit off David Kemp of http://www.value-e-bikes.com.au/, the main reasons for that was that his prices as advertised on the 'net were reasonable and being local I could avoid paying freight. I found David to be genuinely interested in selling a kit that would meet me needs. I ended-up with a 250 W front hub and a 10 amp-hr lithium battery. The kit performed flawlessly and the battery proved adequate for my needs.

Last week the motor lost power, the wheel would turn but at very low revolutions and without power. After several emails and a telephone conversation with David I took the bike up to Noosa for him to have a look at. After testing the battery, wheel and checking all the connections the problem seemed to lie in the controller. David jury rigged a new one in and voilà it worked. After taking the bike for a test ride the bike now is developing full power and achieving it's usual top speed. The problem appears to be solved, if tomorrows commute is trouble free I'll be giving the fix a big thumbs-up.

The replacement controller was supplied under warranty which naturally left me feeling pleased.

My conclusions are;

1. When converting a single-speed bike gear ratios need to thought out carefully;2. A 250W hub motor provides sufficient power for most normal uses3. http://www.value-e-bikes.com.au/ is a supplier well worth consideration

All in all the conversion has been a success, I'm hoping that once I have Tannus tyres on both wheels It will be highly reliable.

It would not be at all strange if history came to the conclusion that the perfection of the bicycle was the greatest achievement of the nineteenth century.

The original plan was to build a bike capable of maintaining a speed of around 27 kph for a distance when fully loaded with lunch, clothes, computer etc for around 40 kms with a depth of discharge of not more than 75% under normal circumstances. The depth of discharge is important as batteries really hate being fully discharged and 75% seemed a good compromise between not using the battery at all and flogging it to death.

Also I was trying to build an electrically assisted bike and not an electric motorbike. For fitness reasons I still wanted to be making a meaningful contribution plus an electric motorbike would raise all sorts of legal issues.

My original plan was for a 350W motor but after running various scenarios (weight, incline, wind speed, power output through this calculator:

I came to the conclusion that although a bigger hub motor would increase speed (by only a small amount) and would increase climbing ability and the ability to punch into a headwind there was a terrible cost to pay in terms of electricity used. Really the 250W was a compromise between speed, power and battery usage. The battery is easily the weakest link and its capacity, cost and weight needs to be considered in any build.

A ferocious headwind is best attacked by hunkering down, reducing total speed and begin serious pedalling and using the motor as a top-up. To simply open the throttle right-up will rapidly drain the battery which could mean walking the last few kms and will reduce battery life.

My gearing started as 46/18 then went to 46/17 and then to 46/16 with each change being a noticeable improvement. Last weekend I rummaged through my bits and pieces and found a 53T chainring, my first thought was that it would be too big, but I ran some numbers and it seemed that it might be ok, although perhaps the gearing might be a tad tall. Anyway I put it on and instantly I have a new bike. The 53/16 gearing allows me to keep up with the motor and to contribute meaningful manual (IMO) manual input.

The other thing that I have done is to fit the puncture proof tyres (700 X 23c) initially to the rear and now on both wheels. The feeling of liberation of being able to remove the tyre levers, CO2 cylinders etc is wonderful.

I’ll be staying with the 53/16 combination for at least the next month or so but currently I feel that I have hit the magic number. One possible future change is to replace the Dicta freewheel with a White Industries DOS ENO (16/18). The 16T would be the one usually used but having an 18T available would give me something to limp home on in the event of electrical failure.

It would not be at all strange if history came to the conclusion that the perfection of the bicycle was the greatest achievement of the nineteenth century.

Great thread. I'm only 7km from home to work atm, so obviously an ebike is unnecessary. However I have seen quite a few commuters zoom past me at a decent pace (I cruise at around 20km/ph) riding flat bar road bikes with a front wheel conversion kit and a battery on the top of the rear pannier rack. I definitely think that if you have longer commutes an ebike or conversion is a good idea as it makes the daily commute just a little easier and manageable for the average person (especially if you live south of the river in Perth and have to ride against strong headwinds almost every afternoon during summer!). A friend of a friend is currently building some ebike prototypes and I have already suggested that he should make a simple singlespeed commuter like what you've put together with puncture proof tyres, mudguards, pannier rack, lights etc. Just jump on it and ride, no worries about hills, heavy loads or headwinds.

Thank you for your comments. My ebike has now travelled 5,500 kms entirely as a commuter. The bike itself has been 100% reliable and with the conversion its ability to punch into a headwind is brilliant and hills have flattened considerably. Now some words regarding the conversion components.The motor has given zero trouble. The battery has also been trouble free and seems as strong as ever. The battery lock however which was just cheap die-cast fell apart. My solution was to simply remove it and replace the switch with one bought from Repco for a couple of dollars. With the controllers I have had two fail. One was replaced on warranty and I bought a second heavier duty one from Solar Bike for $65. The original type was lasting only around 2,000 kms so if no better the Solar Bike one should fail within the next 3 weeks (fingers crossed).

The rack that came with the kit is another story. Now to be fair it is carrying, in addition to the battery a fair amount of weight but not more than would be expected. The tail-light bracket simply fell off. There a 2 cross members (with obviously 4 ‘welds’), 3 of those welds have broken and now the carrier is being held together with a mixture of hose-clamps, pop rivets, bolts and pieces of aluminium. The original extension pieces that bolt to the bottom of the carrier and then to the rear fork simply bent and snapped. I made some replacement ones out of mild steel which bent. Currently I’m using some made out of 3mm thick stainless which are working brilliantly with no sign of bending.

My recommendations at this point are to ensure that the controller is capable of taking the maximum current that is ever likely to flow through it. Remember that if your motor has an output of 250W then the input will be around 310W. Therefore at 36V something like 8.7A will be flowing through the controller but toward the end of the ride when the battery voltage has dropped the current could be as high as 10A. Be prepared to spend some serious dollars on a proper carrier. The cheap Chinese ones are held together with nothing but thinly applied chewing gum and hope.

It’s been an interesting experience and my next build will be similar but some obvious improvements.

It would not be at all strange if history came to the conclusion that the perfection of the bicycle was the greatest achievement of the nineteenth century.

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